The Study On The Feasibility Of THF Wastewater Treatment By Air Striping Method And The Anaerobic Characteristic Of THF

Tetrahydrofuran (THF) has low boiling point and is volatile. And it can mix with water easily. Because THF is a toxic organism it can usually pollute the water during generating PTMEG and hormone. The research was about studying on the feasibility of blowing off THF from the wastewater. At the same time we also studied the biodegradability and toxicity to anaerobic sludge during generating methane of THF and reclamation of sludge under anaerobic condition. In the air stripping experiment we analyzed the factors concerned, such as temperature, the flow of gas, the time of blow and the concentration of THE wastewater, and we gave each factor four different values and made them up orthogonally. The result indicated that temperature was the most important factor that influences the blow-off method among the four factors, time was the second, the third was flow of gas, and the last was inflow concentration. In order to analyze the influence of single factor we made a test to two different concentration wastewater (COD=600mg/l, COD=1100mg/l). And the result from the test showed that under the same flow of gas (0.5m3/h) and the blowing-off time (30min) condition the removal ratio of COD can reach 44%, 60%, 85%, 94%and 98% respectively at 20℃, 30℃, 40℃, 50℃, 60℃. Then we carried out the experiment on the above two different concentration wastewater in two different conditions, one of which was at 30℃, the flow of 0.5m3/h and different blowing-off time, the other at 30癈, 30min and different flow of gas. We found that when the gas-water ratio was identical increasing time could more improve the removal ratio than raising the flow of gas. And the concentration of wastewater had little influence on blowing-off removal of THF. In comparison with THF, it was difficult to remove tetrahydrofurfuryl alcohol andfurfural whose structures were similar with THF by air stripping method. After analyzing the CODbd/COD (6.29%) value in anaerobic static test we knew that THF exhibited bad biodegradability. And when the THF wastewater concentration reached 1700mg/l high the sludge activity of 50% declined. But when THF was removed from the tested water and only acetic acid substrate was added to the water the part of anaerobic sludge activity was recovered., and when the same THF capacity as the first time was added continually after removing the form noxious substance the sludge was induced., so the biological degradation of anaerobic sludge was enhanced.